Back to Article

  • jwilliams4200 - Wednesday, January 11, 2012 - link

    So, let me get this straight. They took a wireless protocol that is touted to be able to achieve 1300Mbps, but they WIRED two pieces of equipment together instead of using wireless, and they only achieve 800Mbps??

    The next obvious question is how bad is the throughput when they, you know, actually use wireless equipment without a wire?
  • UpSpin - Wednesday, January 11, 2012 - link

    Not really correct. They used a wireless transmission, but instead of air, they used a shielded and artificial perfect environment with 3 solid copper cable.
    But you're right, it's a poor result with such a prefect scenario only delivering 60% of the theoretical transfer rate, this means, it will drop at least another 50% using air and environmental noise..
  • jkostans - Wednesday, January 11, 2012 - link

    It's not wireless transmission when the two devices are connected directly with what looks like 3 standard coaxial cables. Coaxial wave guide is not considered wireless by any means, and skipping the antennas is HUGE for the signal to noise ratio. As your signal to noise degrades so does your ability to correctly demodulate the signal. I'm sure it still works but those throughput numbers for the utmost ideal case an nowhere near real world. Reply
  • Guspaz - Wednesday, January 11, 2012 - link

    They wired it together because there'd be way too much interference at a conference like CES from the zillions of other wireless devices. It got 813 Mbps because 1300 Mbps is the PHY rate, not the practical throughput. This is much the same as how a 54 Mbps 802.11g will only give less than half of that (or less) even under ideal conditions.

    There are a variety of reasons why the actual throughput is significantly lower. Overhead is a big one, because there are a lot of layers of overhead involved here, from the PHY all the way down to TCP.
  • jwilliams4200 - Wednesday, January 11, 2012 - link

    Not a good excuse. If there is too much interference for the product to work, even when the devices being linked are RIGHT NEXT TO EACH OTHER, then the product is not very good. Heck, if they were so worried about interference, they could have taken a box, lined it with aluminum foil, and up-ended the box over the two pieces of equipment. Reply
  • MGSsancho - Wednesday, January 11, 2012 - link

    Sure it could drown out everyone else but using power levels not allowed by the FCC. Reply
  • jwilliams4200 - Thursday, January 12, 2012 - link

    The thing about RF is that it attenuates with distance. So all you need to do to "drown out everyone else" with allowed FCC power levels is to put the communicating equipment right next to each other. Reply
  • 0ldman79 - Friday, January 13, 2012 - link

    I run a wireless ISP using 802.11, so I have a tiny bit of experience.

    With something like this, I can see wanting to control your environment a bit. If someone really wanted to make this fail they could bring a 5GHz Motorola Canopy AP, a battery and a tiny antenna in a backpack and completely sabotage the presentation.

    No WiFi device is going to work properly with thousands of clients in a small area. NONE. Even if they're not connecting, the sheer number of client devices seeking a network and transmitting the tiniest bit of data to handshake with a network that they are not even connected to is huge. The noise floor in the 2.4GHz band is probably completely fried there with 5GHz being a little better.

    That being said, 802.11n in full 3x3 is quite impressive, 802.11ac doesn't look revolutionary as it has been presented, quite evolutionary and just the next logical step. The part that looks the most interesting to me is that a multi stream system can communicate with different devices simultaneously with separate streams, at the cost of total bandwidth of course.
  • jwilliams4200 - Friday, January 13, 2012 - link

    I already explained what they could have done if the interference got really bad. It is not hard to rig up a simple Faraday cage with a box and some aluminum foil. It takes no longer than it does to rig up three coaxial cables to wire the boards together. Reply
  • 0ldman79 - Friday, January 13, 2012 - link

    So, you've made a presentation like this with prototype wireless hardware and thousands of smartphones in the room, hmm? Reply
  • jwilliams4200 - Saturday, January 14, 2012 - link

    You do know what a Faraday cage is? If not, you should probably look it up on wikipedia.

    A better question is, why do you make claims that you cannot prove? You said "NONE" of the wireless equipment would work at CES -- you were quite emphatic about the "NONE". That claim can only be proved if you have tested every piece of wireless equipment and found that none of them work. Obviously you are just making it up.

    Given that cell phones can work in such an environment, it is not a big stretch to realize that a well-designed piece of wifi equipment could also work.

    I feel sorry for your customers.
  • LTG - Wednesday, January 11, 2012 - link

    That WiSpy DBx thingy is pretty cool.

    Could that kind of software be created using only the wifi already built into a laptop or tablet?

    I'm not sure what their hardware itself offers other than a larger antenna...
  • DanNeely - Wednesday, January 11, 2012 - link

    My first guess would be no. To keep costs down I assume throwing away high fidelity samples of the RF data everywhere outside the wifi units selected channels frequency. This would make looking at the entire 24/5ghz band rather difficult. Reply
  • MarkYensen - Thursday, January 12, 2012 - link

    Mark at MetaGeek here.

    Chanalyzer software requires data taken from hardware that is not found in most laptops or tablets, namely a narrowband transceiver. This is why the Wi-Spy hardware is necessary to collect raw spectrum data.

    If you're interested heck out this post on how Wi-Spy works:
  • Ryan Smith - Wednesday, January 11, 2012 - link

    You must be having a field day Brian. There's so much wireless interference at CES that your WiSpy should be lighting up like a Christmas tree.

    Though kudos to Buffalo for letting you use it on their 802.11ac gear. And I'm glad to see Buffalo realizes that CES is not the time to rely on WiFi for your product demos.
  • Brian Klug - Thursday, January 12, 2012 - link

    I seriously *am* having a field day :P


Log in

Don't have an account? Sign up now